Tempering saws



W. CLIEMSON.v

Device fer TemperingSaws.A l

No. 29,671. l Patented Aug. 21', 1860.

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IVM. CLEMSON, OF MIDDLETOVTN, NEIV YORK.

TEMPER-ING SAWS.

Specification of Letters Patent No. 29,671, dated August 21, 1860.

To all 'whom it may concern:

Be it known that I, IVILLIAM OLEMsoN, of Middletown, in the county of Orange and State of New York, have invented a new and Improved Device for Tempering Saws; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in which- Figure 1. is a front view of my invention. Fig. 2. a side sectional view of the same, taken in the plane a?, m, Fig. 1.

Similar letters of reference indicate corresponding parts in the two gures.

This invention relates to a new and improved means for tempering saws, that is to say, lowering the temper from an extreme degree of hardness which is first given them, to a proper working temper.

The object of the invention is to obtain a device which may be manipulated with facility and at the same time so act upon the saw as to straighten them while reducing their temper.

The invention consists in the employment of a stationary metallic bed placed over a suitable furnace and used in connection with a suspended metallic pressure block, so operated as to have an oblique, or downward and forward pressure movement, substantially as hereinafter described whereby the desired end is attained.

To enable those skilled in the art to fully understand and construct my invention I will proceed to describe it.

A represents a cast-iron bed which may be of quadrilateral form secured horizontally between two upright plates, B, B, and placed in masonry over a suitable furnace or re chamber. The upper ends of the upright plates B, B, are connected by a cross bar a to the under side of which a spring C is attached-saidspring projecting out equal distances from both sides of the bar a, and having a cast-iron block D suspended from its ends by rods b. The block D, may be about equal in dimensions to the bed A, the former being directly over the latter;

E is a spring which bears against the back end of the block D, and keeps its front end in contact with a traverse bar c, which is attached to the front edges of the upright plates B, B, as shown in Fig. 2.

The front part of the under or face sides of the bed A and block D are beveled or inclined,as shown at ax, a", the former being inclined downward and the latter inclined upward as shown in Fig. 2. The other portions of the faces of the bed and block are perfectly plane surfaces parallel with each other.

On the upper surface of the block D there is secured a block F in which a groove d is made, said groove having an inclined plane G, for its bottom as shown clearly in Fig. 2. j

H, is a shaft which is placed between the two upright plates B, B, and on the shaft H there is placed an eccentric I, which has a lever or handle J attached.

The operation is as follows: The bed A, is heated by the fire beneath it and the spring O is sufficiently strong to keep the block D in an elevated state just above the bed A, the saws which have been previously tempered to an extreme degree of hardness, are taken one by one by the operator and passed between the beveled ends of the bed and plate-the beveled surfaces ax, ax, gradually lowering the temper of the plate so as to destroy its extreme brittleness by the time it reaches the bite or front end of the parallel surfaces of the bed and block. lhen the plate reaches and passes between the 4parallel surfaces above named the operator depresses the lever J, and the eccentric I, acts against the inclined plane G, and forces downward the block D in an oblique direct-ion as indicated by the arrow 1, Fig. 2, and the saw plate is subjected to pressure between the block and bed and at the same time is pressed forward, the saw plate being moved a little forward at each downward movement of the block until it is passed entirely between the bed and block, the heat of the bed reducing the temper of the saw plate and the intermittent pressure of the block in the direction described effectually straightening the saw plate. The block D is elevated by spring C, each time the lever J is relieved of pressure and the spring E throws the block D forward as it rises.

I am aware that cast-iron blocks for tempering saws have been previously used and also that they have been provided with beveled or inclined ends as herein shown for the purpose of gradually lowering the temper before being subjected to pressure, such device being formerly patented by me, the Letters Patent bearing date Oct. 31st, 1854.

In this device, however, a suspended block was not used neither was an oblique movenient given the block to feed the saw plate along between the block and bed. Castiron blocks have also been used, and the saw plate subjected to a direct downward pressure as may be seen by referring to the patent of John Silvester, dated Aug. 31st, 1852, In neither of the devices above named, however, can the saw plates be perfectly straightened and that is a great 0bjection as the saw plates are all more or less subject to buckling in being previously tempered to an extreme degree of hardness.

I do not claim therefore the reducing of the temper of saw plates by pressing them 

